I have a question about using two ethernet adapeters at the same time. I have two computers running Win2K and one running Mandrake 10.1 all with two ethernet adapters. One adapter is connected to a DSL router, and the other to an ethernet hub for local networking. This works fine in the Windows boxes but gives me trouble in the Linux box.

With one adapter (eth0) active, connected to the router, internet access works fine. But when I activate the 2nd adapter (eth1), connected to the hub, internet
access no longer works. I'm not sure if local networking works, since I haven't got past the internet problem yet. BTW, the adapters are using IP addresses in different subnets.

What's going on here? How do internet applications know which adapter to use? I haven't been able to find any parameters about this, and I'm kind of a networking newbie.

Thanks...

Apps decide which path to take depeding on which interface can talk to default gateway (route). Do you have a default route set when both interfaces are active? What are the network/netmask combos you're using? If you're a network newbie, it's easy to screw up netmasks.

Route table.. default route.. how do I do that?

Info:
>ifconfig
eth0 Link encap:Ethernet HWaddr 00:0E:A6:47:43:88
inet addr:192.168.1.101 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::20e:a6ff:fe47:4388/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:334 errors:0 dropped:0 overruns:0 frame:0
TX packets:5671 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:37044 (36.1 Kb) TX bytes:274108 (267.6 Kb)
Interrupt:5 Base address:0x8800

eth1 Link encap:Ethernet HWaddr 00:A0:C9:E8:A0:E8
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:10 Base address:0x8000

Thanks for your reply.

This may help: http://www.brennan.id.au/04-Network_...n.html#routing

BU.

Thanks to sigsegv and Butt-Ugly for the info. I read the Networking-Overview-HOWTO and the The Linux Network Administrator's Guide, but somehow missed the Linux Home Server HOWTO!

My routing table specified eth1 as the default. When I corrected it, the problem was gone.